1 files changed, 24 insertions, 24 deletions

diff --git a/tree.c b/tree.c
index fb38c89..e6ee86e 100644
--- a/tree.c
+++ b/tree.c
@@ -45,7 +45,7 @@ tree_insert(struct tree_node *tree, T key)
 {
         if ( tree == NULL ) {
                 tree = malloc(sizeof *tree);
-                if ( tree != NULL ) {
+                if ( tree ) {
                         tree->key   = key;
                         tree->count = 1;
                         tree->left  = NULL;
@@ -71,7 +71,7 @@ tree_insert_it(struct tree_node *tree, T key)
 {
         struct tree_node *parent = NULL;
 
-        for ( struct tree_node *curr = tree; curr != NULL; ) {
+        for ( struct tree_node *curr = tree; curr; ) {
                 parent = curr;
 
                 if ( key < curr->key ) {
@@ -89,7 +89,7 @@ tree_insert_it(struct tree_node *tree, T key)
         struct tree_node *new_node;
 
         new_node = malloc(sizeof *new_node);
-        if ( new_node != NULL ) {
+        if ( new_node ) {
                 new_node->key   = key;
                 new_node->count = 1;
                 new_node->left  = NULL;
@@ -121,7 +121,7 @@ tree_detach_min(struct tree_node **ptree)
 
         if ( tree == NULL )
                 return NULL;
-        else if ( tree->left != NULL )
+        else if ( tree->left )
                 return tree_detach_min(&tree->left);
         else {
                 *ptree = tree->right;
@@ -253,7 +253,7 @@ tree_copy(struct tree_node *tree)
                 struct tree_node *new_node;
 
                 new_node = malloc(sizeof *new_node);
-                if ( new_node != NULL ) {
+                if ( new_node ) {
                         new_node->key   = tree->key;
                         new_node->count = tree->count;
                         new_node->left  = tree_copy(tree->left);
@@ -340,7 +340,7 @@ stack_push(struct stack *stack, struct tree_node *data)
 {
         struct stack_item *new_item;
 
-        if ( (new_item = malloc(sizeof(*new_item))) != NULL ) {
+        if ( (new_item = malloc(sizeof(*new_item))) ) {
                 new_item->data = data;
                 new_item->next = stack->head;
                 stack->head    = new_item;
@@ -354,7 +354,7 @@ stack_push(struct stack *stack, struct tree_node *data)
 static bool
 stack_pop(struct stack *stack, struct tree_node **data)
 {
-        if ( stack->head != NULL ) {
+        if ( stack->head ) {
                 struct stack_item *next;
 
                 next  = stack->head->next;
@@ -374,7 +374,7 @@ stack_pop(struct stack *stack, struct tree_node **data)
 static struct tree_node *
 stack_peek(struct stack *stack)
 {
-        return (stack->head != NULL) ? stack->head->data : NULL;
+        return (stack->head) ? stack->head->data : NULL;
 }
 /* -->8-- */
 
@@ -426,7 +426,7 @@ queue_put(struct queue *queue, struct tree_node *data)
 {
         struct queue_item *new_item;
 
-        if ( (new_item = malloc(sizeof(*new_item))) != NULL ) {
+        if ( (new_item = malloc(sizeof(*new_item))) ) {
                 struct queue_item *tail;
 
                 tail           = queue->tail;
@@ -448,7 +448,7 @@ queue_put(struct queue *queue, struct tree_node *data)
 bool
 queue_get(struct queue *queue, struct tree_node **data)
 {
-        if ( queue->head != NULL ) {
+        if ( queue->head ) {
                 struct queue_item *next;
 
                 next  = queue->head->next;
@@ -491,7 +491,7 @@ queue_free(struct queue *queue)
 void
 tree_apply_preorder_it(struct tree_node *tree, void (*visit)(T key, void *cl), void *cl)
 {
-        if ( tree != NULL ) {
+        if ( tree ) {
                 struct stack stack;
 
                 stack_init(&stack);
@@ -501,9 +501,9 @@ tree_apply_preorder_it(struct tree_node *tree, void (*visit)(T key, void *cl), v
                 while ( stack_pop(&stack, &tree) ) {
                         visit(tree->key, cl);
 
-                        if ( tree->right != NULL )
+                        if ( tree->right )
                                 stack_push(&stack, tree->right);
-                        if ( tree->left != NULL )
+                        if ( tree->left )
                                 stack_push(&stack, tree->left);
                 }
 
@@ -516,13 +516,13 @@ tree_apply_preorder_it(struct tree_node *tree, void (*visit)(T key, void *cl), v
 void
 tree_apply_inorder_it(struct tree_node *tree, void (*visit)(T key, void *cl), void *cl)
 {
-        if ( tree != NULL ) {
+        if ( tree ) {
                 struct stack stack;
 
                 stack_init(&stack);
 
-                while ( !stack_empty(&stack) || tree != NULL ) {
-                        if ( tree != NULL ) {
+                while ( !stack_empty(&stack) || tree ) {
+                        if ( tree ) {
                                 stack_push(&stack, tree);
                                 tree = tree->left;
                         }
@@ -545,7 +545,7 @@ tree_apply_inorder_it(struct tree_node *tree, void (*visit)(T key, void *cl), vo
 void
 tree_apply_postorder_it(struct tree_node *tree, void (*visit)(T key, void *cl), void *cl)
 {
-        if ( tree != NULL ) {
+        if ( tree ) {
                 struct stack stack;
 
                 stack_init(&stack);
@@ -564,10 +564,10 @@ tree_apply_postorder_it(struct tree_node *tree, void (*visit)(T key, void *cl),
                                 tree = next;
                         }
                         else {
-                                if ( next->right != NULL ) {
+                                if ( next->right ) {
                                         stack_push(&stack, next->right);
                                 }
-                                if ( next->left != NULL ) {
+                                if ( next->left ) {
                                         stack_push(&stack, next->left);
                                 }
                         }
@@ -581,7 +581,7 @@ tree_apply_postorder_it(struct tree_node *tree, void (*visit)(T key, void *cl),
 void
 tree_apply_levelorder_it(struct tree_node *tree, void (*visit)(T key, void *cl), void *cl)
 {
-        if ( tree != NULL ) {
+        if ( tree ) {
                 struct queue queue;
 
                 queue_init(&queue);
@@ -591,9 +591,9 @@ tree_apply_levelorder_it(struct tree_node *tree, void (*visit)(T key, void *cl),
                 while ( queue_get(&queue, &tree) ) {
                         visit(tree->key, cl);
 
-                        if ( tree->left != NULL )
+                        if ( tree->left )
                                 queue_put(&queue, tree->left);
-                        if ( tree->right != NULL )
+                        if ( tree->right )
                                 queue_put(&queue, tree->right);
                 }
 
@@ -661,10 +661,10 @@ tree_preorder_iterator_next(struct tree_iterator *it)
         struct tree_node *node = NULL;
 
         if ( stack_pop(&it->stack, &node) ) {
-                if ( node->right != NULL ) {
+                if ( node->right ) {
                         stack_push(&it->stack, node->right);
                 }
-                if ( node->left != NULL ) {
+                if ( node->left ) {
                         stack_push(&it->stack, node->left);
                 }
         }